Configural processing hypothesis and face-inversion effect

Perception and recognition of faces presented upright are better than Perception and recognition of faces presented inverted. The difference between upright and inverted orientations is greater in face recognition than in non-face object recognition. This Face-Inversion Effect is explained by the "Configural Processing" hypothesis that inversion disrupts configural information processing and leaves the featural information intact. The present chapter discusses two important findings that cast doubt on this hypothesis: inversion impairs recognition of isolated features (hair & forehead, and eyes), and certain facial configural information is not affected by inversion. The chapter focuses mainly on the latter find-ing, which reveals a new type of facial configural information, the "Eye-Illusion", which is based on certain geometrical illusions. The Eye-Illusion tended to resist inversion in experimental tasks of both perception and recognition. It resisted inversion also when its magnitude was reduced. Similar results were obtained with "Headlight-Illusion" produced on a car's front, and with "Form-Illusion" produced in geometrical forms. However, the Eye-Illusion was greater than the Headlight-Illusion, which in turn was greater than the Form-Illusion. These findings were explained by the "General Visual-Mechanism" hypothesis in terms of levels of visual information learning. The chapter proposes that a face is composed of various kinds of configural information that are differently impaired by inversion: from no effect (the Eye-Illusion) to a large effect (the Face-Inversion Effect).